A young volcanic island on Earth may hold clues to former islands on Mars.

In late December 2014, a submarine volcano in the South Pacific Kingdom of Tonga erupted, sending a violent stream of steam, ash and rock into the air. The ash plumes rose as high as 30,000 feet into the sky. When the ash finally settled in January 2015, a newborn island with a 400-foot summit nestled between two older islands – visible to satellites in space. The newly formed Tongan island, unofficially known as Hunga Tonga-Hunga Ha'apai after its neighbors, was initially projected to last a few months, washed away by the ocean. But to the surprise of NASA's science team tracking the evolution of the island using monthly, high-resolution satellites observations from the French space agency's Pléades-1A and DigitalGlobe's Worldview satellites, as well as the Canadian Space Agency's RadarSat-2 observations, the island has survived for more than three years. And, it shows a remarkable resemblance to volcanic formations on Mars. Understanding the processes that shape the Tongan island could provide insights into these Martian features which may have formed in in a similarly wet environment – locations ripe for looking for signs of past life.